Conventionally, lithium ion rechargeable batteries and nickel-metal hydride rechargeable batteries are mounted on vehicles such as electric vehicles (EVs) and plug-in hybrid vehicles (PHVs) as a power storage device for storing power to be supplied to electric motors or the like. Generally, a rechargeable battery includes an electrode assembly of positive electrodes and negative electrodes having active material layers stacked in layers, and a case that accommodates this electrode assembly. One type of case has a case body with an opening for allowing insertion of the electrode assembly, and a lid for closing the opening of the case body. Tabs protrude from one side of the positive electrodes and negative electrodes, and conductor members of respective polarities are joined to the tabs. Electrode terminals of respective polarities are electrically connected to the conductor members.
The rechargeable battery also includes a current interrupting device that interrupts the conduction path electrically connecting the positive electrodes and the positive terminal when the internal pressure of the case exceeds a predetermined level (see, for example, Patent Document 1). In the rechargeable battery of Patent Document 1, the current interrupting device is integrated with the positive terminal, and positioned in a space defined between the inner face of the lid and an end face of the electrode assembly opposed to the inner face of the lid.
In one method of assembling such a rechargeable battery, the electrode assembly and the lid are joined together in advance, and after inserting the electrode assembly into the case body, the lid is welded to the case body. More specifically, positive and negative conductor members are connected to the tabs of corresponding polarities of the electrode assembly, and positive and negative terminals are connected to the conductor members of corresponding polarities, after which part of each electrode terminal is passed through each of two through-holes provided in the lid. The current interrupting device has already been integrated with the positive terminal. The electrode terminals are then fixed to the lid. Thereby, the electrode assembly that has been joined to the electrode terminals via the conductor members is also integrated to the lid. When the lid and the electrode assembly are integrated, the current interrupting device is exposed, facing the electrode assembly. After that, the electrode assembly is accommodated in the case body, and the assembling of the rechargeable battery is complete when the lid and the case body are bonded together to close the opening of the body.